I've had sporadic accounts of this bug, and the easiest thing is if you can grab the current source from svn, and and build DeminaPipelineExtensions.dll yourself. (Just replace the version included in the sample with the one you built.)

What version of Windows (XP, Vista, or 7, and 32, or 64 bit) and what version of version of Visual Studio are you using?

I apologize for the inconvenience, and I'll work on tracking this down.